The present invention relates to a prosthesis for implantation in a body and more particularly to a prosthesis for maintaining the existence of a pocket or surface, either natural or surgically made, in the body and preventing the walls of the pocket or surface from adhering together or from adhering to tissue or organs.
Prostheses for implantation in the human body are well known, having been used for breast augmentation, nose, ear and other body part reconstruction, lymphedema shunts, percutaneous skin access devices, insulin implants, paraplegic implantable cushions, tendon repair prosthesis, etc. Of course, perhaps the most well-known implantable prosthesis, and the most commonly used, is the prosthesis used for either breast reconstruction or breast augmentation. The procedure for using these prostheses typically involves forming a pocket, referred to hereafter as a body pocket, or cavity in a patient's breast and extending submuscularly/subglandularly/subcutaneously upwardly to overlay the superior/lateral part of the chest. This may involve simply the dissection of tissue in the breast area to form the pocket or the dissection of tissue as well as removal of diseased or unwanted tissue. In either case, a fairly large pocket is formed over much of the chest area.
After formation of the body pocket, the selected implantable primary prosthesis (now typically constructed of a silicone envelope in which is contained some type of elastomer gel, liquid saline, or other fluid) is placed at the desired site in the body pocket or cavity which best provides the desired augmentation (or reconstruction) and appearance. Immediately after the implantation, the implanted envelope (as the primary prosthesis) is allowed to "flow" or move within the dissected pocket superiorly and laterally to give the breast an anatomically natural look and feel. However, after time, usually a matter of weeks, facing walls of the body pocket begin to re-adhere and a natural tissue capsule forms around the implant to prevent it from flowing or moving in the pocket. This natural tissue capsule may also contract to tighten around the implanted prosthesis causing it to be unnaturally firm, possibly distorted in form, and sometimes painful.
Of course, with either reconstructive or augmentation surgery of a breast, it is desired that the resulting feature remain as natural in both appearance and feel as possible for as long as possible. With the procedures currently used, achieving this objective consistently is very difficult.